Public Health Guidance for Implementing Decentralized Non- Potable Water Systems SYBIL SHARVELLE A S S OCIATE PROFESSOR COLORADO STAT E UNIVERSITY ONE WAT ER SOLUTIONS I N STITUTE
Capturing Water for Non-potable Use Wastewater from toilets, dishwashers, kitchen sinks, and utility sinks Precipitation collected from roofs and abovegrade surfaces Wastewater from clothes washers, bathtubs, showers, and bathroom sinks Precipitation collected at or below grade Nuisance groundwater from dewatering operations Source: SFPUC
Decentralized Non-potable Water (DNW) Systems A system in which water from local sources is collected, treated, and used for non-potable applications at the building to district/neighborhood scale generally at a location close to the point of generation.
Incorporating Onsite Water Systems at the SFPUC Headquarters Source: SFPUC
Solaire, New York Permitted Since 2003 1000 residents Recycles 25,000 gpd Source: American Water
Eloy Correctional Facilities Complex, Shower Water Recycling Permit issued: 2008 Design flow: 225,000 gpd Source: Showers for 6492 beds are treated to Class A standard & reused for toilet flushing Saves 20 gpd/prisoner of potable water Four facilities, 8178 beds total Recycling equipment, Valentine Engineering Source: Chuck Graff, AZDEQ
Embracing a OneWaterSF
Systems are Happening, But. What are the appropriate water quality standards for DNW Systems? How can we ensure long term reliability of DNW Systems? How can ensure safe water is delivered at all times?
Water Quality: Graywater Use to Flush Toilets BOD 5 (mg L -1 ) TSS (mg L -1 ) Turbidity (NTU) Total Coliform (cfu/ 100ml) E. Coli (cfu/ 100ml) Disinfection California 10 10 2 2.2 2.2 0.5 2.5 mg/l residual chlorine New Mexico 30 30 - - 200 - Oregon 10 10 - - 2.2 - Georgia - - 10 500 100 - Texas - - - - 20 - Massachusetts 10 5 2-14 - Wisconsin 200 5 - - - Colorado 10 10 2-2.2 0.1 4 mg L -1 residual chlorine 0.5 2.5 mg/l residual chlorine Typical Graywater 80-380 54-280 28-1340 10 7.2 10 8.8 10 5.4 10 7.2 N/A
Where we are now with DNWS. State health departments and regulatory agencies need guidance on appropriate water quality standards Current water quality standards are not risk based Everyone has been looking to others for development of standards Guidance on requirements for ensure reliability is needed
.. A risk based approach that is practical for implementation is needed
NWRI Panel formed Sybil Sharvelle, Ph.D. Nicholas Ashbolt, Ph.D. Edward Clerico, P.E. Robert Hultquist, P.E. Harold Leverenz, Ph.D. Adam Olivieri, DrPH, P.E.
Partnering to Develop Risk-Based Public Health Guidance
Stakeholder Engagement Arizona Department of Environmental Quality Austin Water Utility California State Water Resources Control Board, Division of Drinking Water City of Santa Monica, Office of Sustainability and the Environment Colorado Department of Public Health and Environment County of Los Angeles Public Health Denver Water DC Water District of Columbia Department of Energy and Environment Hawaii State Department of Public Health Los Angeles Department of Water and Power Minnesota Department of Health New York City Department of Environmental Protection Portland Water Bureau Province of Alberta Municipal Affairs, Safety Services San Francisco Department of Public Health San Francisco Public Utilities Commission Santa Monica Public Works Seattle Public Utilities United States Environmental Protection Agency, Office of Research and Development Washington State Department of Health
Purpose of this Framework Provide additional information and guidance to state and local health departments that allows these agencies to consider development of a DNWS program that adequately protects public health Developed to address non-single residence applications (multi-user buildings and district/neighborhood scale) Source waters Blackwater Graywater Domestic wastewater Roof runoff Stormwater Condensate Foundation water Nonpotable end uses Toilet flushing Clothes washing Cooling tower Unrestricted-access municipal irrigation
Framework for DNWS (Based on WHO Water Safety Plan)
Process for DNWS Design Select appropriate log reduction target (LRT) for end use Select appropriate treatment process train to achieve LRT Professional Engineer approved Management Plan Specify Responsible Management Entity (RME) Level (1-3) Designate RME Roles and Responsibilities Permit Application Report Submission Specifies design, RME, assurance of reliability, commissioning plan, O&M plan, and plan for distribution system management Signed off by Registered Professional Engineer and approved by regulatory agency Construction and Commissioning Field verification when required Submission of Commisioning Report (feild verification results and final monitoring plan) Operational Monitoring Continuous monitoring at high frequency for surrogate water quality and/or operational parameters correlated to LRTs Controls for out of compliance Reporting Violations and incidents Routine reporting via format that is simple to review Approval and enforcement by regulatory agency
Risk Based Management Considerations
Log 10 Pathogen Reduction Targets Water Use Scenario Log Reduction Targets for 10-4 (10-2 ) ppy Benchmarks Enteric viruses Parasitic protozoa Enteric bacteria Municipal Wastewater Unrestricted irrigation 6.0 (4.0) 6.5 (4.5) 5.0 (3.0) Indoor use 6.5 (4.5) 7.5 (5.5) 6.0 (4.0) Graywater Unrestricted irrigation 5.5 (3.5) 4.5 (2.5) 3.5 (1.5) Indoor use 6.0 (4.0) 4.5 (2.5) 3.5 (1.5) Stormwater 10-1 dilution Unrestricted irrigation 5.0 (3.0) 5.5 (3.5) 4.0 (2.0) Indoor use 5.5 (3.5) 6.5 (4.5) 5.0 (3.0) Stormwater 10-3 dilution Unrestricted irrigation 3.0 (1.0) 3.5 (1.5) 2.0 (0.0) Indoor use 3.5 (1.5) 4.5 (2.5) 3.0 (1.0) Roof runoff water Unrestricted irrigation Not applicable No data 3.5 (1.5) Indoor use Not applicable No data 3.5 (1.5)
Achieving Pathogen LRTs Example log reduction values (LRVs) for Disinfectants Disinfectant Unit Dose for corresponding LRV 1-log 2-log 3-log 4-log Chlorine (free) mg min/l 1.5 1.8 2.2 2.6 3 3.5 Chloramine b mg min/l 370-400 550-600 750 800 Peracetic acid mg min/l NA NA NA NA Ozone mg min/l 0.25 0.3 0.35 0.45 0.5 0.6 UV radiation c mj/cm2 50-60 90-110 140-150 180-200 Advanced oxidation d,e mj/cm2 10-20 50-60 70-80 110-130 Pasteurization (60 C) s 140 280 420 560
Management
Monitoring Routine monitoring of indicator organisms does not provide real time information required for operation of DNWS Cost prohibitive A new monitoring approach: Validation testing Start-up and Commissioning Field verification monitoring Performance target confirmation via challenge testing Continuous verification monitoring Ongoing verification of system performance Continuous observations Surrogate parameters correlated with LRTs Controls for out of specification
Permitting and Reporting 1. Draft PAR submitted, including proposed uses and treatment (if this step is allowed by the jurisdiction s process and it is justified by the project complexity) 2. Final PAR submitted, including plans and specifications, a commissioning plan, and O&M plan 3. Facility Commissioning Report, including results from field verification, and a final monitoring plan, submitted 4. Project permit decision Routine reporting: simple to review Violations and incidents promptly reported
Summary Design Select appropriate log reduction target (LRT) for end use Select appropriate treatment process train to achieve LRT Professional Engineer approved Management Plan Specify Responsible Management Entity (RME) Level (1-3) Designate RME Roles and Responsibilities Permit Application Report Submission Specifies design, RME, assurance of reliability, commissioning plan, O&M plan, and plan for distribution system management Signed off by Registered Professional Engineer and approved by regulatory agency Construction and Commissioning Field verification when required Submission of Commisioning Report (feild verification results and final monitoring plan) Operational Monitoring Continuous monitoring at high frequency for surrogate water quality and/or operational parameters correlated to LRTs Controls for out of compliance Reporting Violations and incidents Routine reporting via format that is simple to review Approval and enforcement by regulatory agency
Acknowledgments WERF Project Number SIWM10C15 San Francisco Public Utilities Commission Water Research Foundation WateReuse Research Foundation NWRI Panel Members NWRI staff for administering and organizing the Panel s activities Stakeholder Group Public Health Coalition Los Angeles County Department of Public Health New York City Department of Environmental Protection San Francisco Department of Public Health Hawaii State Department of Public Health Oregon Department of Environmental Quality Minnesota Department of Health Washington State Department of Health
Thank you